Hydrocarbyl esters of beta-chloro-and beta-bromo-ethanesulfinic acids

ABSTRACT

A method of regulating and/or modifying the growth of plants by applying to the plant locus, certain beta-substituted ethanesulfinic acids, and oxygen esters thereof, is described as well as plant growth regulant formulations containing them. Some of the compounds described for use in the method of the invention are novel.

United States Patent [1 1 Pilgram et a1.

1 1 HYDROCARBYL ESTERS OF BETA-CHLORO-AND BETA-BROMO-ETHANESULFINICACIDS [75] Inventors: Kurt H. G. Pilgram; Earl K.

Jackson; Willy D. Kollmeyer, all of Modesto. Calif.

[73] Assignee: Shell Oil Company, Houston, Tex.

[22] Filed: May 15, 1972 211 Appl. No.: 253,356

Related U.S. Application Data [63] Continuation-in-part of Ser. No.162.709. July 14.

1971, abandoned.

FOREIGN PATENTS OR APPLICATIONS 2,005,514 9/1970 Germany 260/456 1 Apr.8, 1975 OTHER PUBLICATIONS Carre et al., Chem. Abstract, Vol. 29, p.6206-6207. (1935).

Kondo et al., Tetra. Letters, No. 32, pp.

Etlis et al., 2h. Abst. Khim," Vol. 35, No. 3, pp. 475-479, 1965.

Douglas, J. Org. Chem," Vol. 30, pp. 633-635, 1967.

Primary Examiner-Leon Zitver Assistant Examiner-Norman Morgenstern [57]ABSTRACT A method of regulating and/or modifying the growth of plants byapplying to the plant locus, certain betasubstituted ethanesulfinieacids, and oxygen esters thereof, is described as well as plant growthregulant formulations containing them. Some of the compounds describedfor use in the method of the invention are novel.

4 Claims, N0 Drawings BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to the discovery that betachloroandbeta-bromoethanesulfinic acids and esters can be employed to regulateand/or modify the growth of plants.

2. Description of the Prior Art Certain of the lower alkylethanesulfinatc esters which are active in the method of the inventionare known compounds. German Pat. No. 2,005,5l4 discloses the methyl,ethyl and isopropyl esters of 2- chloroor bromoethanesulfinic acid asanti-cancer agents. The preparation of the tertiary butyl ester of2-chloroethanesulfinic acid is disclosed in V. S. Etlis, et al., JournalGeneral Chemistry U.S.S.R 35. 472-75 l965 Also, one of the free sulfinicacids useful in the method ofthe invention. 2-chloroethanesultinic acid,is disclosed in A. I. Titov and A. N. Baryshnikova, Dukl. Alma. Naultx,SSR, I57, 68l (I964) and H. Distler, Angcw. Chem. Inlt'rnat. lid. 4, 300(1965). However, no reference is known which discloses or suggests theplant growth regulant properties of these known com' pounds or the classof compounds as a whole which have been found to be active in theprocess of the invention. Other related art is G. Hesse, et al, Chem.Ber. 90, 2l06 (I957) which discloses the barium salt ofZ-hydroxyethanesulfinic acid and US. Pat. No. 2,4l2,9()9 which disclosesa general reaction wherein unspecified alkyl or substituted alkylsulfinyl halides may be reacted with alcohols, phenols, etc., to formproducts which are useful as bleaching agents, dyes, plasticizers and avariety of other uses, but not including plant growth regulators.

SUMMARY OF THE INVENTION Surprisingly, it has now been discovered thatcertain ethanesulfinic acids and oxygen esters thereof wherein the betacarbon atom of the ethylene moiety is substituted with bromine orchlorine, can be employed to regulate and/or modify the growth ofplants. Depending on variables such as the species of plant treated,plant maturity at time of treatment, the quantity and concentration ofgrowth regulant used. the specific compound used, and the formulationemployed, these compounds when applied to the plant locus exhibit a widevariety of useful plant growth regulating properties. Some of the plantgrowth regulant effects which have been observed include the promotionof early and more uniform fruit ripening and/or abscission, accelerationof leaf abscission, promotion of flowering, stimulation of sprouting oftubers, stimulation of seed germination, destruction of apical dominancein tubers causing lateral buds to sprout, increased formation of rootinitials on tomato stems, the causation of tomato leaf epinasty anddwarfing of plants. It will be recognized that biological response suchas that realized from the process of the instant invention, whenutilized as a cultural practice in the agricultural industry, canprovide a valuable means of increasing crop productivity while at thesame time reducing the labor and expense necessary to produce the crops.

The invention accordingly, is the use of beta substituted ethanesulfinicacids and esters, hereinb fore described as plant growth regulators andplat growth regulant formulations containing them.

2-Bromoethanesulfinic acid and many of the sulfini esters useful in theprocess of the invention are nove Therefore, the scope of the presentinvention also er compasses these novel compounds. 2

DESCRIPTION OF THE PREFERRED EMBODIMENTS The beta-substitutedethanesulfinic acids and este1 found useful to regulate the growth ofplants accordin to the method of this invention are represented by f0mula I:

wherein X represents bromine, chlorine or alkoxy of u to 3 carbon atomsand R is hydrogen, alkyl of up to 2 carbon atoms, aryl of up to 10carbon atoms, alken: of up to 8 carbon atoms or alkynyl of up to 4 carboatoms. Any of these alkyl groups may be of eitht straight chain orbranched chain configuration.

Exemplary species of the class of the invention ir clude:

propyl 2-bromoethanesulfinate 2-bromoethanesulfinic acid phenyl2-bromoethanesulfinate naphthyl 2-chloroethanesulfinate propynyl2-bromoethanesulfinate Many of the compounds active in the method of thinvention have not previously been known in the ar Thus, the followingare considered to be novel con pounds and form a preferred aspect ofthis inventio (symbols refer to formula I, above):

I. Sulfinic Acids The compound wherein X is bromine and R is hydr gen.

ll. Sulfinate Esters Compounds wherein X is chlorine or bromine and isalkyl of from 6 to 20 carbon atoms, alkynyl of up I 4 carbon atoms,alkenyl of up to 8 carbon atoms or ar of up to 10 carbon atoms.

Of the generic class of compounds useful in tl method of this invention,certain species in the sulfin' ester subclass are especially effectivein regulating tl' growth of plants, thus compounds wherein X is Chltrine, and R is alkyl of up to 20 carbon atoms or alken' of up to 8carbon atoms make up another preferred a pect of this invention.

Specific examples of this preferred subclass includ methyl2-chloroethanesulfinate amyl 2-chloroethanesulfinate 3-butenyl2-chloroethanesulfinate heptyl Z-chIoroethanesulfinate decyl2-chloroethanesulfinate 3-pentenyl 2-chloroethanesulfinate The compoundsof this invention may be applied 1 seeds prior to planting or to soilsurrounding the plant or to plants, pre-emergence, or at harvest tomodi' and/or regulate the growth of the plant, or optional may beapplied to stimulate, regulate and/or modi' ripening of the harvestedportion. For applicatio compounds of the invention, being either solidor liqu at ambient temperatures, may be formulated using conventionaltechniques and employing adjuvants and/or modifiers which are known inthe agricultural chemical art to provide compositions in the form ofwettable powders, dusts, granules, pellets, solutions, emulsifiableconcentrates, emulsions and pastes.

Preferred for use on maturing plants or harvested crops are thoseformulations which furnish the active ingredient to the plant locus inliquid or paste form. These preferred formulations would includewettable powders, solutions, emulsifiable concentrates. emulsions andpastes. Wettable powders are waterdispersible compositions containingthe active ingredient in proportions ranging from 10 to 907r of thetotal composition, and an inert solid carrier such as one of the naturalclays or a synthetic mineral filler derived from silica and silicate.Optionally, such wettable powder may also contain 3-107? of a dispersingagent and where necessary -l0'72 of stabilizer(s) and/or other additivessuch as penetrants or stickers. The term solution includes both aqueousand non-aqueous solutions of the compounds of the invention. Certain ofthe compounds of the invention are soluble in aqueous media and can beformulated and applied in aqueous solution at concentrations up to Othercompounds of the invention are less or sparingly soluble in water andexhibit proportionally higher solubility in non-aqueous solution and maybe formulated and applied at concentrations of up to 50%. Theemulsifiable concentrates contemplated for use in the method of theinvention usually contain, in addition to the solvent and, whennecessary, co-solvent, 10-50% w/v active ingredient, 2-20% w/vemulsifiers and 0-207! appropriate additives such as stabilizers,penetrants and corrosion inhibitors. Pastes are compounded so as toobtain a stable flowable product and usually contain 10-60% activeingredient, 220% of appropriate additives, and. as carrier, water or anorganic liquid in which the plant growth regulator is substantiallyinsoluble.

For season long treatment, i.e., application at time of planting orapplication to plants in early stages of growth, or for otherspecialized applications, solid formulations of the compounds of theinvention may be desired. Suitable solid formulations would includedusts, granules and pellets. Dusts usually have a composition similar tothat of a wettable powder but without a dispersant, and normally contain/2 to 10% of plant growth regulator. Dust may also be formulated asconcentrates which are then usually diluted further with solid carrierin suitable blending equipment prior to use in the field, Granules andpellets are usually prepared to have a size between 10 and 100 BS mesh,and may be manufactured by agglomeration compaction or impregnationtechniques. Generally, granules will contain /2257( of plant growthregulator plus additives such as stabilizers, slow-release modifiers,binding agents, etc. Except where indicated otherwise, all percentagesgiven in this and the preceeding paragraph are percentages by weight.

To achieve the plant growth regulating and modifying effectshereinbefore described, formulations of the compounds of the inventionmay be applied directly to the plant fruit or as foliar-soil treatments,seed treatments, foliar treatments or soil treatments. The rate ofapplication will be dependent on the type of application techniqueutilized as well as other factors such as the particular active agentused, the particular formulation employed, the particular species ofplants involved, the maturity stage of the plant, the types of effectdesired and the local conditions; for example, temperature, humidity,soil moisture, chemical make-up of the soil and the like. In general,for plantsin agronomic environment, rates from 0.05 to 20 pounds peracre can be used to stimulate and/or modify plant growth. However, thepreferred rates for most uses range between 0.l and 5.0 pounds per acre.For application to the plant fruit or harvested crop, the rate ofapplication may range between I and 20,000 ppm (parts per million basedon total fruit weight) with rates of from to 4,000 ppm being preferred.

The compounds of this invention as described by formula 1, above, may beprepared by the following synthesis techniques.

I. Sulfinic Acids (compounds wherein R is hydrogen) The beta-substitutedethanesulfinic acids of this invention may be prepared by the reactionof a betasubstituted ethanesulfinyl chloride of the formula llX-CHgCHgS-Cl II wherein X is bromine or chlorine, with water. Thisreaction is suitably carried out in an inert organic solvent such asether and the by-product hydrogen chloride, which is generated in thereaction, is effectively removed by sparging the reaction mixture withnitrogen during the reaction period.

The beta-substituted ethanesulfinyl chloride described by formula ll canbe prepared by oxidative chlorination of the correspondingbis(beta-substitutedethyl) disulfide wherein the beta substituents ofthe disulfide are the same as the beta substituent on the sulfinylchloride. This technique, which utilizes a general method described byI. B. Douglass and R. V. Norton, Journal of Organic Chemistry, 33, 21041968) for conversion of certain disulfides to sulfinyl chlorides,involves the reaction of chlorine gas with thebis(betasubstituted-ethyl) disulfide in glacial acetic acid. Thebis(beta-substituted-ethyl) disulfide reactants utilized in thesynthesis technique described above are known in the art, e.g., see G.Y. Epshtein, et al, J. Gen. Chem. USSR, 34, 1961 (1964); see also,Fuson, et al., J. Org. Chem. 11, 491 (1946).

ll. Sulfinate Esters All of the beta-substituted ethanesulfinate estersdescribed by formula 1 above, except compounds wherein R is aryl. may beprepared by the reaction of a betasubstituted ethanesulfinyl chloride ofthe formula II with a hydroxy compound of formula [I] as illustrated byequation I, below 0 0 X-CHgCHgS-Cl ROH X-CHgCHgS-OR Equation I II IIIwherein X is as defined in formula I above and R represents all themoieties defined for R in formula I above except aryl. This reaction issuitably carried out in an X-CH CH S-Cl ROTl X- ClbCll SOR TlCl II VIEquation II The products of this reaction are most suitably purified bymolecular distillation.

The following examples are illustrative of methods of preparing thecompounds of this invention and their use in regulating plant growth. Inthese examples, parts by weight (w) and parts by volume (v) bear thesame relation as the kilogram to the liter and all temperatures are indegrees Centigrade. In all cases. the structures of the compoundsprepared were confirmed by infrared spectra, nuclear magnetic resonancespectra and elemental analyses.

EXAMPLE I Z-Chloroethanesulfinic Acid Bis(2-chloroethy1) disulfide wasoxidatively chlorinated according to the general method disclosed in l.B. Douglass and R. V. Norton. Journal ()fOrgunic Chemistry, 33. 2104(1968) as follows: Bis(2-chloroethyl) disulfide (38.0 w) was chargedinto a reaction vessel containing glacial acetic acid (24.0 w) and themixture was cooled to Chlorine gas was introduced to the cooled solutionat a rate such that the reaction mixture was maintained at about 10. Thechlorine addition was continued until the deep orange color of thereaction mixture disappeared. The solution was then distilled at reducedpressure to yield a clear liquid. Z-chloroethanesulfinyl chloride (50.4w), boiling point 8282 under reduced pressure (12 torr).

Water (3.6 w) was added in one portion to a solution of2-chloroethanesulfinyl chloride (29.4 w) in ether (250 v). The reactionmixture was held for one hour at ambient temperatures during which timea vigorous stream of nitrogen was bubbled through the mixture. Uponcompletion of the hold period, the reaction solution was concentrated bydistillation in a vacuum to give a colorless liquid (26.4 w). Furtherpurification of this liquid by molecular distillation at 75 and l X 10;torr provided a colorless viscous oil, 2-chloroethanesulfinic acid (14.5w).

EXAMPLE ll 2-(Ethyl)hexyl 2-chloroethanesulfinate A stirred portion of2-chlor0ethanesulfinyl chloride (16.2 w) prepared as in Example 1,cooled to 15 to -30C. was treated dropwise with 2-ethylhexanol 13.0 w)under a nitrogen atmosphere. Upon completion of the addition theexternal cooling was removed and the reaction mixture was allowed tostand for 16 hours at ambient temperature. Distillation through a 20 cmVigreux column afforded a clear white liquid, (2- ethyl)hexyl2-chloroethanesulfinate (14.7 w) boiling at l 10 to 1 12 under reducedpressure (0.3 torr).

EXAMPLE lll Butyl 2-chloroethanesulfinate 2-Chloroethanesulfinylchloride (16.2 w), prepared as in Example 1 was dissolved in dry ether(130 v) and the solution was cooled to -l5. Normal butanol was addeddropwise under a nitrogen atmosphere to the cooled solution. Uponcompletion of the addition period the reaction mixture was allowed towarm to ambient temperatures and the solvent was removed by distillationin a vacuum to yield a colorless liquid. butyl 2-chloroethanesu1finate18.5 w).

Example IV Phenyl 2-chloroethanesulfinate A suspension of thallium(l)phenoxide (28.6 w) in dry ether (100 v) was rapidly treated with2-chloroethanesulfinyl chloride, prepared as in Example 1. The slurrywas vigorously stirred for 1 hour at ambient temperature with exclusionof moisture. Removal of thallium(l) chloride by filtration andevaporation of the ethereal filtrate solution gave an oil. The oil wasthen subjected to molecular distillation in a wiped-film apparatus at 75(l X 10 torr) to give phenyl 2-chloroethanesulfinate (122 w) as a mobileliquid.

Example V Following procedures similar to those given in previousexamples, the following other species of the compounds of the inventionwere prepared (symbols refer to formula 1).

Eagle I lahle l('ontinued Melting Point. C

or Boiling Point. C (torr) Fruit Abscission Washington Navel orangeswere harvested in a manner such that the fruit was still attached to 4inches of stem having two (2) clusters of leaves. The pull forcerequired to cause abscission of the fruit from the cut stems was 14-16pounds. The harvested oranges were then segregated into groups of five(5) oranges each (stems and leaves still attached) and the segregatedgroups were sprayed to dripping with several concentrations of methylZ-chloroethanesulfinate in aqueous solution. A water treatment was usedas a control. Some oranges began to drop off the stems two days after.treatment with the higher concentrations of methylZ-chloroethanesulfinate while the fruit in the control groups remainedattached to the stems. The rates of application as well as theobservations of the fruit abscission occurring seven (7) days aftertreatment for both the treatment groups and the control group arerecorded in Table 11 below.

EXAMPLE vn Fruit Ripening Green field picked tomatoes were randomizedand segregated into a treatment group and a control group.

The tomatoes in the treatment group were painted with a 1,000 ppmaqueous'solution of methyl 2-chloroethanesulfinate containing 0.2%Tronic as a surfactant. The tomatoes in the control group were paintedin the same manner with the base solution. Eighteen days after treatmentall the tomatoes in the treatment group were fully red whereas with thecontrol group only two of the tomatoes had begun turning red twenty daysafter treatment.

EXAMPLE Vlll Stimulation of Seed Germination Under normal conditionsexperience has shown that lebur seeds were soaked for one hour in eitherwater or methyl 2-chloroethanesulfinate at 1,000 ppm w/v water. Allseeds were planted and allowed to germinate over a ten day period.Treatment with methyl 2-chloroethanesulfinate increased seed germinationby 25% over the controls.

EXAMPLE IX Stimulation of Tuber Sprouting Twenty-four yellow nutsedgetubers were soaked in a ppm aqueous solution of methyl2-chloroethanesulfinate for ten minutes, blotted dry and sealed in abottle. A like number of tubers were soaked in water and sealedaccording to the same procedure. Six days after treatment all (100%) ofthe treated tubers had sprouted whereas only 81% of the control tubershas sprouted. Also, the number of shoots formed per tuber increased from1.3 for the control group to 1.6 for the treatment group. Treatment withmethyl 2-chloroethanesulfinate. therefore, stimulated sprouting anddestroyed the normal dominance of the apical bud thus allowing lateralbuds to sprout.

EXAMPLE X Leaf Abscission Individual branches of Washington Navel orangetrees were treated with aqueous solutions of several of the compounds ofthe invention. Each of the compounds tested was made up as a 2000 ppmsolution in water containing 0.2% Tronic as surfactant. A total of 100ml of each of the resulting solutions was applied as a foliar spray to asingle branch of Washington Navel orange trees. Seven days aftertreatmentsome of the leaves on the treated branches became stiff,although still green. and began to fall from the trees. Observations ofthe defoliation caused by each chemical six weeks after treatment arerecorded in the following ta ble. Evaluation of defoliation was based onfour classifications: '1 to 10%, 11 to 30%. 31 to 60% and 61 to 100%abscission of the leaves originally present.

Table [11 Compound Tested Percent Ahscission methyl2-chloroethanesulfinate l to 10 ethyl 2-chloroethanesulfinate 1 to 10isopropyl 2-chloroethanesullinate l to 10 hexyl 2-chloroethanesulfinatel l to 30 octyl Z-ehloroethanesullinate l to 10 None of the leavesdropped from the untreated control branches or those sprayed with thebase solution.

EXAMPLE Xl Fruit Ripening the following color rating: green points).breaker I point). 1/2 orange (2 points). full orange (3 points) and redripe (4 points). When all tomatoes in a group are fully ripe the scorewill be 40 points thus equaling 100%. The results are listed in Table IVbelow.

Table IV Percent Ripeness Days After Treatment Treatment 1 2 3 4 5 6 7l0 Control 3 3 8 18 28 38 63 68 80 93 98 Z-chloroethanel3 30 48 55 68 7578 85 90 95 sulfmic acid ethyl Z-chlorocthanesulfinate l0 10 30 38 45 5358 73 83 83 93 Z-propynyl 2- chloroethane- 8 60 68 78 80 83 90 98sullinate isopropyl 2- chloroethane- 8 10 28 38 53 60 68 73 75 95sulfinate alllyl Zchloroethanesullinate 8 ll 22 28 42 58 67 72 86 95oelyl Z-chloroethanesull'imne 8 8 15 25 35 48 5 58 65 83 98 butylZ-chIoro' ethanesulfinate 5 l5 3 40 58 70 78 78 80 83 95 hexylZ-chloroethanesullinate 5 8 33 43 55 63 78 85 93 93 I00 Z-ethyl hexylZ-ehloro- 5 5 I8 23 33 55 68 70 78 88 98 ethanesullinate methyl2-chloroethnnesulfinate 3 5 l0 18 33 38 48 50 63 70 88 eieosy]2--chloroethanesullimtte 3 8 20 30 33 50 58 70 80 85 93 As indicated inthe table above. the compounds of the invention in this test were mosteffective in stimulating early ripening of the test plants. This effectis illustrated by the relative ripeness values at 5 days aftertreatment.

EXAMPLE XIV Fruit Ripening This test was conducted to evaluate theefficacy of the compounds of the invention as ripening agents for maturefruit prior to harvest. i.e.. fruit still attached to the growing plant.Individual clusters of mature green cherry tomatoes grown in agreenhouse were treated with the compounds of the invention while stillon the vine. For treatment, the test compounds were made up in aacetone/water solution at a concentration of 1000 ppm and each testsolution was applied thoroughly to LII a different set of 4 clusters oftomatoes. each cluster I having 4 to 6 mature tomatoes. One set oftomatoes was treated with the base solution for control purposes. Theresults are listed in Table V below.

EXAMPLE XV Fruit Ripening Picked. green, untreated bananas wereseparated and randomly grouped for treatment. The treatment consisted ofspraying each of the different treatment groups. one untreated groupbeing retained as a control. with a L000 ppm aqueous solution of one ofthe following compounds of the invention: methyl 2-chloroethanesulfinateand hexyl 2-chloroethanesulfinate. In all cases the treated bananasturned completely yellow two to five days before the untreated bananas.

EXAMPLE XVI Leaf Epinasty Leaf epinasty is a hormonal response whichoccurs in plants wherein the upper side of the leaf stalk grows morerapidly than the lower side causing the leaf to bend downward. Toevaluate for leaf epinasty response. three and six week old tomatoplants were randomly segregated into groups of three plants each andeach group was sprayed with a different compound of the invention at aconcentration of 2.000 ppm in aqueous solution containing 0.2% Tronicsurfactant. One unsprayed group was retained for control. The plantsunder test were evaluated on a periodic basis throughout the test forepinasty response; the observations of leaf epinasty which had occurredthirteen days after treatment are recorded in Table V] below. Evaluationof the degree of leaf epinasty is based on four classifications: noepinasty indicating normal horizontal leaf growth, complete epinasty(90) indicating that the leaves grew vertically downward around thesteam and 30 or 60 epinasty indicating intermediate downward growth ofleaves.

Table Vl Compound Tested Degree of Leaf Epinasty cetylZ-chloroethanesulfinate 30 methvl 2-chloroethanesulfinate 30 laurylZ-chloroethanesulflnate complete allyl 2-chloroethanesulflnate 30 methylZ-bromoethanesulfinate 60 EXAMPLE XVlll Leaf Epinasty A second leafepinasty test was performed on tomato plants. In this test phenyl2-chloroethanesulfinate as the test compound was applied as a foliarspray to 3 different tomato plants. Two plants were 37 days old. Theolder plants were 14 inches high with 10 leaves and the younger thirdplant was 23 days old. The older plants were l4 inches high with 10leaves and the younger plants were 10 inches high with 8 leaves. Twoages of plants were included because the older plants usually are moresensitive and give a more rapid hormonal epinasty response. The testcompound was dissolved in acetone and diluted to 2.500 ppm with watercontaining 0.4% surfactant (Wilsco Foamspray). A 10 ml volume of thetest compound so diluted was applied as a foliar spray to 3 tomatoplants. The treated plants were evaluated for epinasty (bending ofleaves downward toward the base of the stem) 20 hours after treatment.The test was again evaluated for epinasty as well as phytotoxicity fourdays after treatment, to determine if the epinasty effects haddissipated. The results of the test including those obtained for thecontrol" (base solution without test compound) are recorded in Table lXbelow. The table heading leaves normal after four days" designatesvisual observation of whether any effects of epinasty remained 4 daysafter treatment.

Table lX Percent of Leave: Showing Epinasl Respgnse Leaves Inter- NormalNo Slight mediate Complete Afler Phyto- T r r 4 Days Toxicity Control[00 0 0 0 Yes None Phenyl Z-chloroctlunesulfinate 0 59 8 33 Yes None Weclaim as our invention: 1. A compound of the formula I X-CH CH 4.Z-Propynyl 2-chloroethanesulfinate.

1. A COMPOUND OF THE FORMULA I
 2. A compound according to claim 1 wherein X is bromine and R is alkenyl.
 3. A compound according to claim 1 wherein X is chlorine and R is alkyl.
 4. 2-Propynyl 2-chloroethanesulfinate. 